The effect of inhibiting fatty acid oxidation with (plus) octanoylcarnitine in perfused rat livers under various physiologic and pathologic circumstances was evaluated. These studies clearly showed that such inhibition markedly increases hepatic triglyceride synthesis and secretion into the perfusion media. The hepatic triglyceride was secreted as a particle whose density was less than 1.006. BIBLIOGRAPHIC REFERENCES: Raskin P., McGarry J.D. and Foster D.W.: Independence of cholesterol and fatty acid biosynthesis from cyclic AMP concentration in the perfused rat liver. J Biol Chem 249:6029, 1974. Raskin P., Marks J.F., Burns H., Plumer M.E. and Siperstein M.D.: Capillary basement membrane width in diabetic children. Amer. J. Med. 58:365, 1975.